Bascule-bridge.



T. E. BROWN, Jn.

BASCULE BRIDGE. APPLicATroN'FlLED AuG.2. wir.

Patented Jan. 29, 1918-.

4 SHEETS-SHEET 1.

mgm,-

T. E. BROWN, JR.

BASCULE BRIDGE,

APPLICATION FILED AuG.2, 1917.

Patented Jan. 29, '1918.v

4 SHEETS-SHEET 2.

T. E. BROWN, 1n.

` BASCULE BRIDGE. .APPLICATION'FILED AUG.2.1911.

PatentedA J an. 29, 1918 4 swims-SHEET s.

THOMAS ELAIS BROWN, JB., 0F MORRISTOW'N, NEW JERSEY- I nascenti-naines.

Specication o! Letters Patent.

Application led August 2, 1917. Serial-No. 184,128.

To all whom it." may concern:

Be it known that I, THOMAS ELLIS BROWN, Jr., a citizen of the United States, and a resident of Morristown, in the county of Morris and State of New Jery, have in vented certain new and useful Improvements n-Basculediridges, of which the following is a specilication.

Thls invention relates to. improvements in bascule bridges. One of the objects of my invention is to balance the movable span of a bascule bridge in all its positions by means of a counterweight. and a counterweight carrying structure adapted to travel backward and forward as the bridgeopens and closes. `Another object of my inven tion is to operate the movable span by moving the counterweight structure backward and forward, and still another object of my invention is to move said structure back ward and forward by simple rotation of the wheels or rollers upon which it is mounted, whereby I am enabled to greatly simplify the operatingmachinery. c

Il accomplish these objects by carrying the counterweight on a suitable structure, such as a trusscd frame girder or beam, adapted to travel backward and forward as the span opens and closes and pivotally connecting said structure to the moving span in a manner such that said traveling struc ture will have a definite position relatively to said span for every position of said span, the -traveling structure being preferably mounted on rollersor trucks 'carried'by suitable tracks.

Referring to the drawings which accompany the' specification to aid the description,

Figure 1 is aside view of a bridge of the preferred form of my construction. Fig. 2 is an end view of Fig. 1.

Figs 3 and. 4 are an end view and sido view respectively, and on an enlarged scale,

of-the truck and operating mechanism.

Fig. 5 is a 'diagram of a method in outthe profile of the track.

gs. 6, 7, 8, 9 and 10 are side views of for lay- `modified Iorms of my invention.

Similar letters of reference 'refer to similar parts in all the-gures Referring to Fig. 1, B is a movable span, P the pivot hinge or trunnion about which it. jxotates, lA., Arare abutments, the abut- Vment .supporting the track T.

1s a counterweiglit,.supported. on the framed structure or 'rder C which is pivotally connected to tglie movable span at a. suitable point I. Sa'id structure or girder C is supported at the pivot E by the truck K which is provided with wheels or' rollers R. Said truck K being free to movebackward and forward on the track T as the span B opens and closes.

The position of the pivot E of said truck K oy the construction shown is always at a constant distance, equal to length I, E, from the point of attachment I 0n the movable span. c. g. is the center of gravity of the movable span. G is the center of gravity of the weight W, and the arrangement is such that the weight W balances the Span B in all its positions as is hereinafter eX- plained. It will be understood that' the description refers to one side of the bridge only and that the parts described will in generalbe duplicated on 'the other side of the bridge, as shown in rig. 2, but the coun-- tenweight W mayextend clear across the bridge if desired. The frame C and tracks girders of the movable span.

The bridge may be operated in any suit` suitable brake o should be provided. Elec-A tric current for the operation and control of the motor M may be carried to the truck by trolley or flexible wires or in any other suitable manner. It will be readily understood that an internal combustion engine or othermotive power may be used instead of the motor M.v i

lVhen sald rollers R are rotated in a direction the reverse of thehands of a clock the truck K travels backward together with the structure C. and the span B opens and-.

when the rollers R arev rotated in the opposite direction the truck K and structure C travel forward and the span B c oses.

It will be noted see Fig. 1, that the truck K is between lthe counterweight WV and the Patented J an. 29, 1918.

T are preferably placed in the planes of the pivot I of the moving span and therefore 110 the load on the truck K is greater than the weight W, Aand .hence there is suliicient pressure and adhesion between the rollers R andv track T to provide for the required tractive force, and therefore simple rotation of the rollers R may be used to operate the bridge, and the operating struts, racks or gear segments usual with bascule bridges, though applicable, are not necessary with my construction.

Referring to Fig. 5, in order that the moving span will be balanced in all its positions the profile of the track. T must be so shaped that the path of the pivot E of the counterweight supporting structure will be such that the vertical tali of the center of gravity G of the weight Wr will be always proportional to the vertical rise of the center of gravity o. g. of the moving span, or aigebraically expressed, if N is the, ratio of the weight of the counterweight W to the weight of the moving span B thenv P, c. g. withthe horizontal for the lowest position of the span; rzthe radial distance from pivot P'to the center o f gravity o. g.; andazthe angie through which the bridge has moved; then to maintain the required baiance (sine (a +13) :haine ,6)

` ed a suitable point for the connecting pivot bit' I and having chosen a suitable positlon for the centerof gravity G of the Weight W which is usuaily dependent on the head room required over the roadway, I draw an arc from the pivot P as a center through the pivot I and of a length corresponding with the total angular movement of the span, I then divide this are into a number of parts representing various angular movements of the span and obtain the points i, 3 4, etc. I then determine the re uired fall of` the center of gravity G of t e Weight W .from its original position, corresponding to these angular movements of the span by means of the foregoing formula, and draw horizontal lines k2, h3, t, etc., at the distances so found below the original positionh ,oi-said point G. I then, from the corresponding points 2, i, 4, etc., draw arcs of radius IG, intersecting the horizontal lines ft2, 7a3, t, etc., and thus obtain points g2, g3, g4 in the path of point G. I then swing arcs from the points g2, g3, g, etc., and `:from the points 2, i, i4, etc., of radius respectively equal to GE and IE, and the intersection of these arcs will be points e, e3, e4, etc.; in the path of the pivot E. By drawing a line at a proper distance from the path of E thus found-to suit the c0n. struction of the truck 1,(,the profile of the track T is obtained.

Various modifications of my invention may be used to' suit special conditions. Fig. 6 shows the counterweight frame C connected by pivot I2 and link C1 to the moving span instead of directly at pivot I. This construction enables cross bracing to be used between the counterweight frames on each side of the bridge for their entire length and above the line of roadway clear ance.

Fig.-7 shows the counterweightgirder C supported above the truck K by a hinged strut F, and this form is especially suitable for a through bridge with deep trusses.

In the forms shown in Figs. Gand 7, the pivoted distance struts Q, pivoted to the span Bat suitable points I1, are desirable, in order to locate the position of the trucks K relatively to the movable span to enable the profile of the track T to be easily deV termined and to insure stable equilibrium.

Figs. 8 and 9 show forms of my invention which are useful where approach spans D are used and particularly when it is desirable to use straight horizontal tracks. In these forms in order that the tracLs may be horizontal the point of attachment I of the beam C to the moving span B should be on the line P-o. g. joining the pivot .1

and the center of gravity c. g. of the moving span, as explained in application Serial, No.

145,578, filed January 31st, 1917, and the pivot E of the truck K shouldvbe placed on the line I. G. and at a distance L from f point I as given by the following equation llt:

. may be made shallow and the of a movable span,

is used Ias shown in Fig. 9, the g'irder D truck may be extended upward to pivot. E, thus forming a movable tower K.

In all of the forms shown in the figures any required` number of wheels or rollers may be used to suit the loads t0 be carried. and the operating mechanism may rotate one or more or all of the Wheels as may be necessary to produce the 14required traction. In light bridges a single roller may be used instead of a truck.

It' will be readily understood that the arrangement for ope/ration shown in Figs. l, 2 and 3, and 4 is applicable to all the gures and is the preferred arrangement but that other methods of operation auch as are commonly used with bascule bridges be used it' desired. will be understood that the mechanism shown in the liguies in connection with pl ate girder spans" are also applicable to triiss bridges and vice versa.

Now having described my improvements, what I claim as my invention is:

1. The'combination in a bascule bridge,- pivotally connected at its-liecl to a fixed part of the bridge, a counterweightl carrying structure pivotally connected to said span, a counterweglit on the rearward end of said structure and a een tral support for said structure adapted to travel backward and forward on a substantially horizontal track, as said span rotates to its open and closed positions. v

2. The combination in a bascule bridge, of a movable span pivotally connected at its heel to a fixed part of the bridge, a coiinteriveight, a carrying Structure for said countcrweight pivotally connected to said span, a truck Supporting said structure ben tween said counterweiglit and said span, and adapted to travel backwardand forward on 4a track as said span rotates, said track so shaped that said counterweight. balances said span in-all its positions.

3. The con'ibination in a bascule bridge of a movable span pivotally connected at its heel to a fixed part of the bridge, a counterweiglit., a carrying structure for said counterweight pivotally connected to said span, a. truck supporting eaid structure beclosed' positions.

.means to .move'eaid structure backward and forward and rotate said Span to its open and closed positions.

i 4. In a bascule .briilge,` a movable span rotatably connected at its lieel to' a fixed part of the bridge structure, a traveling frame pivotally connected to said span andrmov able therewith, a countcrweight carried on the rearward end of `said frame, support` ing means for said traine between Said coiniterweight and said span, a substantially horizontal track for said supporting means and said track adapted to control the vertical niotion of said counterweight to balance said span in all its positions.

5. ln a bascule bridge, a movable span rotatably connected at its heel to a iixed part of tbe bridge structure,a travelin fra-.ine pivotally connected to said span an movable therewith, aA counter Weight carried on the rearward end of a truck supporting said frame between said counterwciglit and Said span, a track .for

said frame, A

said truck adapted to control the vertical G. In a bascule bridge, a movable span rotatably connected at its heel to a fixedv part of the bridge structure, a traveling frame pivotally connected to said span and movable therewith, a counter4 weight can ried on the rearward end of said frame, a truck supporting said frame between said counterweight and said span, ai track for said truck adapted to control the vertical inotion'of said counterweight to balance saidA span in all its positions, and means to move said frame backward and forward and thereby rotate said span to its open and `Signed at New York city, in the county of New York, and State of New York, this 31st day of July, A. D. 1917.

THOMAS ELLIS BROWN, JR. 1Witneeses Trios. E. BROWN,

Rrra WVEiss. 

